In recent years, image pickup apparatuses employing solid-state image pickup elements such as CCD (Charge Coupled Device) type image sensors or CMOS (Complementary Metal Oxide Semiconductor) type image sensors have been downsized, and mobile information terminals such as cell-phones equipped with these information pickup apparatuses have come into wide use.
On the other hand, the image pickup lens to be installed in the image pickup apparatus is not only requested to be further smaller but also is requested increasingly to have higher performance, being affected by the trend of higher number of pixels of the image pickup element.
As an image pickup lens for this application, there is disclosed a three-element image pickup lens wherein a meniscus-shaped positive first lens whose convex surface faces the object side, a meniscus-shaped positive second lens whose convex surface faces the image side and a negative third lens whose concave surface faces the image side are provided in this order from the object side, as one that is capable of having higher performance than that of a one-element or two-element-lens and is not affected by downsizing (for example, see Patent Document 1).
(Patent Document 1) TOKUKAI No. 2003-322792
However, in the image pickup lens described in the Patent Document 1, there is used a meniscus-shaped negative third lens whose convex surface faces the image side. Therefore, a peripheral part of the third lens swells toward the image side. It causes that a position of the lens surface on the optical axis recedes greatly from the image pickup element, when the third lens is arranged not to touch a substrate arranged on the rear side. Thus, a back focus cannot be made small and it leaves room for further improvement in downsizing. Further, aberration correction is not sufficient.